1. Field of the Invention
The present invention relates to a graphics system for providing simplified pointer selection of objects.
2. Description of Prior Art
It is a well known problem that it is difficult to select small objects with a mouse or other pointer. This problem arises most often, in a cluttered environment, or in the presence of unexpectedly selectable objects. Examples are CAD and VLSI design systems, where selection can be difficult even for an experienced user. A similar problem arises when selecting a moving target. It can also arise for partially disabled users or users not accustomed to mice, when selecting small or thin objects. An example of a prior art document which attempts to solve this problem is U.S. Pat. No. 5,808,601 which discloses an object attractor mechanism where a pointer is attracted to objects based on a calculated mass for the object.
The present invention on the other hand provides a graphics system for a graphical user interface in which a plurality of screen objects are displayed comprising: targeting means comprising means for determining a screen object targeted by said pointer; selection means comprising means for reading a pointer selection and means for selecting a targeted screen object; said graphics system being characterized by: said targeting means comprising means for generating, according to the proximity of the pointer position to a screen object, a weighting associated with each screen object, said weighting being in inverse proportion to the displayed size of the associated screen object, and wherein said determining means is adapted to determine said targeted screen object according to the respective weightings associated with said screen objects.
The invention operates by permitting the pointer to select small objects when positioned near but not over an object. In the preferred embodiment, objects are considered to lie within a target area (which will be referred to as an extended target area) larger than the object""s visible area. Preferably, the smaller an object, the more the target area extends around the object.
Preferably, as the pointer moves, a weighting is calculated for each screen object. The object with greatest weight, if it is over a predetermined threshold, is taken as the selectable object. The xe2x80x98weightxe2x80x99 metric is defined to decrease with increasing geometric distance between the pointer and an object, and to increase for small target objects.
It will be seen that, while multiple identification of objects can happen with objects that visibly overlap, or where their extended target areas overlap, using the invention, it is possible, where a small object lies inside or on the edge of a larger one, for a pointer positioned over the large one and near but not over the small one to identify and make selectable the small object.
In one embodiment of the present invention a graphics system for a graphical user interface in which a plurality of screen objects are displayed is disclosed. The graphics system includes a targeting means comprising means for determining a screen object targeted by said pointer, and a selection means comprising means for reading a pointer selection and means for selecting a targeted screen object.
The graphics system can be characterized by the targeting means including a means for generating, according to the proximity of the pointer position to a screen object, a weighting associated with each screen object, the weighting being in inverse proportion to the displayed size of the associated screen object, and wherein the determining means is adapted to determine the targeted screen object according to the respective weightings associated with the screen objects.
The targeting means is only responsive to the pointer selection to determine the targeted screen object. The targeting means is responsive to each pointer position movement to determine the targeted screen object and wherein the graphics system is adapted to highlight said targeted screen object.
The determining means is adapted to determine a screen object is targeted only if a maximum object weighting exceeds a pre-determined threshold.
The weighting is limited by a maximum growth factor.
In yet another embodiment of the present invention, a control panel is associated with the graphics system, the control panel is responsive to user interaction, and further, updates of the maximum growth factor.
The graphics system can be embodied in an operating system. An application can include the graphics system, the application is one of a general purpose application or a dedicated application.
In one embodiment of the present invention, a computer program product comprising computer program code stored on a computer readable storage medium for, when executed on a computing device, controlling the targeting of screen objects, the program code comprising the graphical system.
In an alternative embodiment of the present invention, a graphics system is disclosed for a graphical user interface in which screen objects are displayed, and a method of targeting a screen object includes the steps of determining a screen object targeted by said pointer, and reading a pointer selection and selecting a targeted screen object.
The method can be characterized by generating, according to the proximity of the pointer position to a screen object, a weighting associated with each screen object, the weighting is in inverse proportion to the displayed size of the associated screen object, and wherein the determining step is adapted to determine the targeted screen object according to the respective weightings associated with the screen objects.